Apparatus for transporting concrete



Sept. 12, 1933.

E. A. HOFFMANN' APPARATUS FOR TRANSPORTING CONCRETE Filed Aug. 24, 1927 3 Sheets-Sheet 1 Sept. 12, 1933.

E. A. HOFFMANN 1,926,622 APPARATUS FOR TRANSPORTING CONCRETE 7 Filed Aug. 24, 1927 5 Sheets-Sheet 3 INVENTOR. if 3 fan/0rd 4 0/9770/7/7 1:9.

A 7? NbYS.

Patented Sept. 12, 1933 UNITED STATES APPARATUS Fox raANsrotsTrNG V CONCRETE Edward A. Hoffmann, Reading, Pa., assignor, by

direct and mesne assignments, to Clinton Motors Corporation, Reading,

tion of New Yorl- Application August 24, 1927.

Pa, a corpora Serial No. 214,995

- 6 Claims. (o1.ss 73) This invention relates to a methodof and apparatus for transporting concrete and has to do. more particularly with large operations where, for practical purposes, it is desirable to mix concrete at the central stationjand to thereupon transport it to different distinct localities for pouring or otherwise.

Large building operations of the present day have demonstrated that instead of mixing concrete on particular jobs where it is to be used, itis more economical to mix the concrete at a central station to which the constituent materials can be more easily and economically transported and after mixingv the concrete to deliver such concrete is mixed condition to the respective jobs or building operations. A: .the present time there are a few such central mixing plants where the concrete is mixed and thereupon transported to the respective jobs, but numerous difficulties havearisen which threaten the practicability of these plants and up to the present time no satisfactory solution of the problem has been advanced.

For example, while it is highly economical to mix concrete at a central station and transport it in mixed condition, it is found, in practice, that when mixed concrete is placed in a truck andtransported for any appreciable distance, the constituents of the concrete'will stratify in accordance with their specific gravities'by the time the truck reached its destination, and in order toobtain a proper mixture of the mass, it is'necessary to re-mix the concrete on the job that after concrete has been transported in a truck fora distance that the stone will settle will stratify above the stone. p

It is frequently necessary under present practice to employ men to board the truck with shovels and shovel out the stone and gravel that accumulate in a closely compacted mass on the bottom of the truck. Pumping trucks are frequently employed in the transportation of con-- crete, but even with such trucks shoveling generally has to be resorted to. if the concrete is carried for any appreciable distance.

As a result of these facts, th concrete as it leaves the truck and unless properly mixed, will not form a homogeneous masonry which its constituent parts or proportions should properly produce. For these reasons and. others, careful builders are continuing to mix concrete from its dry constituents on the respective jobs and conto the bottom, and the sand, water and cement befcre pouring; In otherwords, it has been found tiguous to the place Where it is to be poured in spite of the higher cost of suchoperations.

I have exhaustively experimented in the handling ofconcrete for a prolonged'period and, as a result of this exhaustive experimentation, I have found that the only way in which concrete can be mixed at a central station and delivered there from to respective building operations ,at distant localities, is to maintain a condition during trans: portation which will preclude Stratification or settling out of the constituentsof the mixture.

I have discovered that ifconcrete is mixed in desired proportions and then transported in such a manner; as to effect a continual agitation of the massduring transportation that the concrete will reach such destination in as good .a condi-- tion for pouring, as it was when it left the central station.- This constitutes the basis of the method of this invention which, generally stated, consists in producing an aqueous mixture of concrete at a central station, thereafter loading itupon avehicle, utilizing-the vehicleto-transp'ort it to a, distant station, maintaining the constituents of the mixturejin continual agitation of the character to preclude settling or stratification and discharging said mixed and agitated concrete from the vehicle at the place where it is to be'used.

In practically carrying out the invention, I employ a vehicle having thereon a rotary cylin-. der mounted to rotate on a horizontal axisand with which means is associated to constantly rotate the cylinder during transportation of the concrete. The concrete after ,being thoroughly mixed at a central station is deposited in the' rotary cylinder of the vehicle and whileit is thus transported to the job or buildingoperat'ion, the cylinder is constantly revolved until the vehicle reaches its destination, there, by means of suitable hoisting mechanism associated with the ve-' hicle, the cylinder is tilted to discharge the contents thereof'at a suitable point forpouringor otherwise, the cylinder being provided with an outlet or discharge gate through which the con'-- crete may exit therefrom. I I r I find it highly practical to employ a motor truck as a vehicle and to derive'power for rotating an dtilting the cylinder from the engine of the truck through suitable mechanical driving connections hereinafter more fully explained.

The. present invention is directed not only to the broad method to which I have referred, but also embodies structural features of truck con--' struction hereinafter more .fully explained and pointed out in the appended claims, 7 The accompanyingdrawin'gs illustrate one form of apparatus for carrying out the method of this invention, but the construction therein, shown.

is to be understood as illustrative only and not as defining the limits of the invention.

Figure 2 is a front elevation'of the construction shown in Figure lwith the chassis'frame of the ,vehicle shown in section. 10

Figure 3 is a rear elevation of the construction shown in Figure 1; I a V Figure 4 is a diagrammatic view illustrating driving means for the controlling and tilting of the cylinder to discharge the contents thereof. Referring to the drawings l designates the chassis frame of a motor truck or other suitable vehicle. The running gear and driving connections for the truck chassis have not'been shown as they-may be conventional and any form of motor truck may be employed without departing from the invention.

Mounted upon the frame 1 is a cradle 2 pivoted on a transverse axis 3 for tilting movement after the-manner of a dump truck body. Mountedon the frame 1, at 'theforward end of the cradle 2, is alifting apparatus 4',.shown as a hydraulic lift. The lift embodies a cylinder 5 mounted on the truckand within each cylinder operates a piston 6 hydraulically controlled. The top of the piston carries a yoke lat'theoutboard ends of which are mounted pulleys 8. Cables 9 are secured at one end of each of them to the chassis frame and extend upwardly over the pulleys 8 andthence' downwardly and are secured to brackets 10 carried by the cradle, so that through operation of the hydraulic lift, the forward end of the cradle may be raised or lowered to tilt said cradle on the transverse shaft 3.

Supported near'thefront' and rear ends of. the cradle on suitable structural iron supports 11 or otherwiseare two bearings 12 and onthese bear- .ings a hollow cylinder 14 is mounted to revolve. The bearings are bracedby braceslS totake up,

end thrust and to mount the cylinder so that it will rotate without appreciableend play 01' racking oflits supports. l I I Trunnions 15 positioned coaxialwith the cylinder and at opposite ends thereof are .mounted in the bearings 12 and thus the cylinder is supported for rotation on its longitudinal axis.

:At one point'in the periphery of the cylinder,

it is preferably provided with a filling openingv adapted to be normally closed by a cover 16 maintained in closed position by fastening devices 17.;

Moreoverg'the rearend of the cylinder is provided with a discharge opening positioned near the periphery of the cylinder and normally closed by a sliding gate '18. The gate has brackets 19 which-are connected by links 20 to crank arms 21 on a rockshaft 22 (see Fi ure 3'), and on the shaft is secured an operating handle '23 by which the cranks may be actuatedtoslide the gate 18 radially of the cylinderfor thepurpose of opening and closing the discharge opening.

It will be noted that with the crank arrangement shown the cranks 21 and links 20 function after the manner of a toggle which, when in the condition shownin Figure 1,,will serve to lock the gate in closed position and preclude its inadvertentopening.

Encircling the cylinder isa ring gear24firmly affixed to the cylinder and this ring gear meshes with the pinion 25 mountedon .a stub shaft 26.

The stub shaft is connectedby a universal'joint' 27 with a drive shaft 28. The forwarcl end 9 the drive shaft is squared at 29 and extends into a squared hole-of a sleeve 30 into the opposite end of which extends the squared end 31 of a stub shaft 32 connected by a universal joint 33 to a power, shaft 34. The squared ends of the shafts 28 and 32 are adapted for sliding movement within the sleeve 30 to compensate for slight longitudinal shifting of the shaft 28 when the cradle is tilted. In lieu of the squared ends,

however, thesershafts may be splined within the sleeve 30 or otherwise suitably connected for the same purpose as specified.

Mounted onthe power shaft 34 is a gear or sprocket 35 driven by a gearor chain 36 from any suitable part of the motor of the truck chassis. A clutch of any conventional form may be included in these connections, so as to render the rotation of the cylinder controllable by the driver of the truck.

It will'beapparent from the description thus far advanced that after the concrete has been thoroughly mixed, it may be introducedinto the filling opening by opening of the cover 16 and after introduction into the cylinder the truck may then leave for its destination. As ,soon as the concrete is introduced, however, the cylinder is caused to revolve through the connections described and continues to revolve during the transportation of the concrete to its destination.

When the truck reaches its destination, the rotation of the cylinder is discontinued and the hydraulic lift operated to tilt the cradle and thus automatic means for stopping the cylinder after it has been inclined at the desired maximum angle. This means is shown diagrammatically in Figure 4. Here the reference character 38 designates a conventionalpump for supplying liquid under pressure to the hydraulic lift. The pump is shown as having a drive pinion 39 driven from a gear 40 on a drive, shaft 41. The drive shaft 41 is mounted for longitudinal reciprocation in suitable bearings (not shown) and isprovided with 125 a gear 42 adapted, in the illustrative form shown, to mesh with the gear 43 which is the constant counter shaft gear of the transmission of the truck. 44. designates thetransmission case. A handle 45 is connected to the shaft 41 and through manipulation of the handles, the gear 42 may be thrown into and out of mesh with the gear 43 by sliding the shaft longitudinally. while the gear '40 remains at all times inmesh with the gear 39 of the pump. I

A cable 46is secured to the other end of the shaft through any suitable connection 47. and after passing over a', pulley 48 is connected to the yoke '7 of the hydraulic lift.

Under normal conditions, the gear 42 is out loo The shaft 41 immediately commences to operate the pump 38 through the gearing connection shown and liquid is fed to the hydraulic lift to bring about the dumping operation. As

the yoke 7 approaches the upper end of its'maxim lm travel, it places the cable 46 under tension and the continued upward movement of the yoke will draw the shaft 41 to the right in Figure 4 and disengage the gear 42 from the gear 43 before any damage can be done to the apparatus; The structure shown in Figure 'has been found to give very satisfactory practical results, but I wish it understood that this structure is for the purpose of illustration only and that changes may be made therein without departing from the invention. It will further be understood that suitable valves are associated with the hydraulic lift to relieve the liquid when it is desired to lower the cradle to its horizontal position.

Actual practice has demonstrated that with the mechanism which I have described, it is entirely feasible and practical to mix concrete at a central station and transport it for many miles to building operations without in anywise impairing the mixture or permitting stratification or solidification thereof. Due to the constant rotation of the cylinder, there is a constant agitation of the mixture which effectually precludes the Stratification or solidification and the concrete is thus delivered ready for use without deterioration.

I wish to call particular attention to the fact that the cylinder should be made water tight in order that none of the water embodied in the concrete mixture can escape during transportae ierent parts of the concrete will be constantly changing. My experience has shown that it is wholly practical to employ a cylinder which has a smooth, unencumbered interior, and that concrete can be kept in proper condition by a cylinder so constituted and without the employment of rotary paddles, blades, etc. This is desirable as a smooth surface cylinder will discharge more efficiently and may be kept clean at all times.

The accompanying drawings show the invention in its preferred practical form, but the invention is to be understood asfully commensurate with the appended claims.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is: i

1. In an apparatus of the character described,

a truck embodying suitable drive mechanism in combination with a cylinder mounted on the truck for rotation on a normally substantially horizontal axis and for tilting .movement, said cylinder having a smooth surfaced unencumbered interior provided with a chargingopening having a suitable closure adapted to normally seal the opening, and means driven from the drive'mechanism of the truck for impartingrotation to the cylinder after it has been charged and sealed.

2. In an apparatus of the character described, a truck embodying suitable drive mechanism in combination with a cylinder mounted on the truck for rotation on a normally substantially horizontal axis and for tilting movement, said cylinder being provided with charging and discharging openings having suitable closures adapted to'normally seal the opening, and said, cylinder being interiorly free of encumbrances and provided with a smooth unencumbered inner surface, means driven from the drive mechanism of the truck-for imparting rotation to the cylinder after it has been charged and sealed, and means also driven fromthe drive mechanism-of the truck for tilting the'cylinder when desired to discharge the same through the discharging opening. 3

3. In an apparatus of the character described,

' a truck chassis embodying suitable propelling necting the cylinder to the propelling mechanism of the truck to rotate the cylinder for the purpose of precluding solidification or stratification of the contents thereof, operative connections 7 between the cylinder and the propelling mechanism for tilting the former through power derived from the latter, and means controlled by movement of the former for automatically disconnecting the former from the latter after the cylinder has been tilted to a predetermined extent.

.4. In an apparatus of the character described, a truckchassis embodying a suitable power plant in combination with a cradle mounted for pivotal movementon the chassis, a cylinder mounted on the cradle for rotation on a substantially horizontal axis, said cylinder being provided with a discharging opening normally sealed, means for operatively connecting the cylinder with the power plant of the chassis to rotate the cylinder while in sealed condition to preclude solidifying'or stratificationof the contents thereof, tilting mechanism mounted on the chassis and operatively connected to the cradle to tilt the cradle ina position to dump the contents of the cylinder when the discharging opening is,

unsealed, operating connections between the tiltoverlying the rear end of the body frame, a tiltable frame disposed between said tank and said body frame, a pivotal connection between said tiltable frame and'the rear end of said body frame, a pair of longitudinally aligned trunnion bearings carried and supported bysaid tiltable frame, said tank having trunnions supported by said bearings, and means for rotating said tank.

6. Apparatus for transporting ready-mixed concrete from a mixing plant to a place of usage comprising, a vehicle, a tank on the vehicle mounted to rotate on a substantially horizontal axis, and means for giving a rolling over motion to the tank, the tank being without mixing blades and without aninterior shaft along its axis of rotation, and the peripheral tank wall being substantially circular in planes at right angles to the axis of rotation of the tank. 1

EDWARD A. I-IOFFMANN. 

